Mitsubishi Electric PQHY-P72ZLMU-A Service Handbook page 354

[ IX Troubleshooting ]
Error display/failure condition
[1] Inverter related errors
4250, 4220, 4230, 4240,4260, 5301, 0403
[2] Main power breaker trip
[3] Main power earth leakage breaker trip
[4] Only the compressor does not operate.
[5] The compressor vibrates violently at all times or makes an abnor-
mal sound.
[6] Compressor rotation speed does not reach the specified speed.
[7] Noise is picked up by the peripheral device
[8] Sudden malfunction (as a result of external noise.)
HWE15150
Measure/inspection item
Check the details of the inverter error in the error log in X LED Monitor
Display on the Heat source Unit Board.
Take appropriate measures to the error code and the error details in ac-
cordance with IX. [2] Responding to Error Display on the Remote Con-
troller.
<1> Check the breaker capacity.
<2> Check whether the electrical system is short-circuited or ground-
faulted.
<3> If items cause is not <1>or <2> are not the causes of the problem,
see (3)-[1].
<1> Check the earth leakage breaker capacity and the sensitivity cur-
rent.
<2> Meg failure for electrical system other than the inverter
<3> If the cause is not <1>or <2>, see (3)-[1].
Check the inverter frequency on the LED monitor and proceed to (2) -
[4] if the compressor is in operation.
See (2)-[4].
<1> Check for problems with compressor current and heatsink
temperature.
<2> Check for imbalance in power supply voltage. *Approximate target:
3% or less.
<1> Check that power supply wiring of the peripheral device does not
run close to the power supply wiring of the heat source unit.
<2> Check if the inverter output wiring is not running parallel to the
power supply wiring and the transmission lines.
<3> Check that the shielded wire is used as the transmission line when
it is required, and check that the grounding work is performed prop-
erly on the shielded wire.
<4> Meg failure for electrical system other than the inverter
<5> Attach a ferrite core to the inverter output wiring. (Contact the fac-
tory for details of the service part settings.)
<6> Provide separate power supply to the air conditioner and other
electric appliances.
<7> If the error occurred suddenly, a ground fault of the inverter output
can be considered. See (2)-[4].
*Contact the factory for cases other than those listed above.
<1> Check that the grounding work is performed properly.
<2>Check that the shielded wire is used as the transmission line when
it is required, and check that the grounding work is performed prop-
erly on the shielded wire.
<3>Check that neither the transmission line nor the external connec-
tion wiring does not run close to another power supply system or
does not run through the same conduit pipe.
* Contact the factory for cases other than those listed above.
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